Our UCLA team in partnership with United Healthcare (UHC) proposes to form a cooperative agreement with the CDC and NIDDK to evaluate the impact of two highly innovative programs in Medicaid known as the Accountable Care Communities (ACC) Program and the Health Home (HH) Program. Both programs are delivery system transformations with on-the-ground partnerships to support improvements in care and population management strategies for Medicaid beneficiaries, many of whom have diabetes and other complex care needs. The implementation of the ACC and HH programs by one of the nation's largest for-profit insurance companies who has over 1 million new Medicaid enrollees since 2012, represents a unique and very timely evaluation of real-world interventions. The overall goal of the research is to employ rigorous empirical evaluation of the impact of these innovative programs on the delivery, outcomes, and cost of care for adult Medicaid enrollees with diabetes. Our specific aims are as follows: 1) To evaluate whether the Medicaid ACC Program which provides on-the-ground partnerships that embed UHC transformation consultants and nurses into practices to support improvements in care, provides access to complete health care and community wide data analytics to support population management and includes practice level financial incentives, such as shared savings programs, will lead to improvements in adherence to medications and diabetes processes of care, in A1c and LDL-c control, fewer emergency room visits and hospitalizations and lower overall costs of care. 2) To evaluate whether the Medicaid HH Program which targets patients with serious chronic physical and mental health conditions who also have high social needs, and high costs of care, and provides them intensive, individualized care management from an integrated team inclusive of community health workers will lead to improvement in adherence to medications and diabetes processes of care, in A1c and LDL-c control, fewer emergency room visits and hospitalizations and lower overall costs of care. 3) To fully participate in a collaborative multi-institution netwok designed to strengthen the research methods for evaluating natural experiments across all sites, and to advance the best analytic methods for natural experiments in the US research community Our UCLA team will use quasi-experimental designs, de-identified data from UHC, and state-of-the-art modeling strategies to achieve these aims. Our team's 11 years of highly productive partnership with UHC, 19 years of experience evaluating policy-relevant natural experiments, most recently in the NEXT-D study, and 12 years of leading study coordination across national collaboratives, will help ensure our success.